Kotobukiya's Roll figure kit should be released in a matter of weeks if not days. As a sign of its impending production, a hobby magazine has released some shots of the figure crafted with a test run of the mass production parts. This should give you an idea of what to expect when you make the figure yourself. While painting is certainly not required, it is needed to make the figure look as good as the promotional prototype.
A couple things to note. First, the kit will definitely come with eye plates that have eyes painted on them, just like the Rockman figure does, so don't worry about being stuck with a zombie Roll. Additionally, while her ribbon is made with white plastic here, odds are good that particular part will be painted green during production. This similarly occurred with the Rockman figure, whose buster gauge was painted yellow after being molded with white plastic (you can an example of this before the painting here).